Ultrasonically welded switch construction and method



United States Patent 3,485,982 ULTRASONICALLY WELDED SWITCH CON- STRUCTION AND METHOD Alan E. Maire, Goshen, Ind., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed Oct. 14, 1965, Ser. No. 495,893 Int. Cl. H01h 9/02, 9/00 U.S. Cl. 200-168 15 Claims This invention relates to a novel leaf switch construction and method of making the same.

Previously, leaf switches have been assembled by assembling a multiplicity of switch leaves interspersed with a plurality of insulating blocks and then securing the whole stack with either rivets or machine screws. Many disadvantages are connected with this practice, which are eliminated by the practice of this invention.

This invention eliminates all insulating fiber pieces, rivets and machine screws of the previous practice.

According to this invention a plurality of molded plastic blocks, or plastic switch blade holding members, are provided. A plurality of switch blades are held by such blocks or holding members, with movable end portions of the blades extending from the holding members. Then the holding members may be bonded or ultrasonically welded together to complete the switch assembly without the use of such previously insulating fiber pieces, rivets and machine screws.

Also, if desired, a frame construction may be provided, with frame portions secured to some of the blocks or holding members, such frame portions being also bonded or ultrasonically secured to the blocks, or holding members.

Other features are apparent from this description, the appended claimed subject matter, and/ or the accompanying drawings, in which:

FIGURE 1 is a perspective view of a switch assembly embodying this invention, with parts broken away, to expose certain other parts.

FIGURE 2 is a side view of FIGURE 1, also with parts broken away.

FIGURE 3 is a diagrammatic view, taken from line 33 of FIGURE 1, showing one step in the method of assembling this construction.

FIGURE 4 is an end view of FIGURE 3, taken from the right end of FIGURE 3.

FIGURE 5 is a view somewhat similar to FIGURE 3, but showing further steps in the assembly operations.

FIGURE 6 is a cross section taken along the line 6-6 of FIGURE 5.

FIGURE 7 is a view, similar to a portion of FIGURE 5, but showing a further step in the assembly process.

FIGURE 8 is a diagrammatic view, in greatly reduced scale, showing, diagrammatically, an apparatus for practicing the method.

FIGURE 9 is a diagrammatic enlarged cross section of a groove construction which may be used in connecttion with this invention.

FIGURE 9A is a view similar to FIGURE 9, but showing a thicker and narrower blade than is shown in FIG- URE 9.

FIGURE 10 is an end elevation of the completed switch construction as formed in FIGURES 1-8.

FIGURE 11 is a view similar to FIGURE 10, but showing another embodiment.

FIGURE 12 is a top view of a stack of blades which may be used in the formation of a switch construction similar to that illustrated in FIGURES 1-10.

Certain words may be used in this specification and in the claimed subject matter which indicate direction, relative position, and the like. Such words are used for the sake of brevity and clearness. However, it is to be understood that such words are used in connection with the illustrations in the drawings, and that in actual use the parts so described may have entirely different direction, relative position and the like. Examples of such words are vertical, horizontal, upper, lower, etc.

In practicing the invention, a switch assembly 18 may include a plurality of molded plastic blocks, or plastic switch blade holding members, 20 and 22, FIGURES 1-10. A plurality of switch blades, such as 23 through 27, may also be provided.

These switch blades may have held or holdable portions 30, FIGURES 3 and 12, to be held by the holding members 20 and 22. The blades may also have freely movable end portions 32, which extend from the hold ing members 20 and 22 at one end. The blades also may have terminal connection ends 34 at the other end.

Some of the blade members may have electrical contacts 36 at their freely movable end portions 32. These electrical contacts are adapted to engage each other during the operation of the switch construction, as is well known. The held portions 30 may have notches 38, which engage the ends 40 of the blocks 20 and 22, and hold the blades against longitudinal movement, after they have been secured within the blocks 20 and 22.

The blocks or holding members 20, 22 are provided with opposed grooves, notches or irregularities 42.

The grooves, notches or irregularities 42 may hold the blades 23-27 firmly locked in place after the blocks or holding members 20 and 22 have been bonded, or ultrasonically secured together.

As shown in the drawings, the blades 23-27 may be relatively wide and relatively thin, compared to their width. The grooves 42 may be relatively deep and narrow, as compared to their depth.

An actuator carrying frame 44 may be ultrasonically secured to the blocks or blade holding members 20, 22, and the like. The actuator frame 44 may be U-shaped, if desired, and may have rail portions or legs 46 and 48. These rails 46, 48 may engage, respectively, the outer surfaces of blocks 20 and 22. The base 50 of the U-shaped frame may have an externally threaded mounting cylinder 52, which is firmly secured to the base 50, and which may be used for mounting the switch construction on a panel, or the like. This mounting cylinder 52 may contain a two or three position snap acting actuator 54. The actuator 54 may be provided with an operating handle 56 and an actuator end 58, which may engage and actuate the blade construction, such as through the medium of the actuated blade 25.

The actuated blade 25 may be insulatedly connected to the freely movable blades 24 and 26, by means of a relatively rigid connector insulative plate 60. The blades 23 and 27 may be relatively stationary, but may yield slightly, as illustrated at 23, in FIGURE 2. The blade assembly 24, 25 and 26 may be downwardly biased, in FIGURE 2, so that such assembly will move the blade 26 into contact with the blade 27, when the actuator end 58 is moved to its downward position, not shown. However, when the actuator end 58 is moved upwardly, it moves the blade 25 to the upper position illustrated in FIGURE 2. At that time, the entire blade assembly 24, 25, and 26 is moved upwardly, so that the blades 23 and 24 engage each other, as illustrated in FIGURE 2. The blade 23 may yield slightly when so contacted, as illustrated in FIGURE 2.

The snap acting actuator 54 may be a two position or three position actuator. That is, the handle 56 may be moved to its lowermost position, as illustrated in FIG- URE 2, electrically to connect the blades 23 and 24. Also, the handle 56 may be moved to an upper position, electrically to connect the blades 26 and 27. This is accomplished by the downward bias of the blade bank 24, 2-5 and 26, which will follow the downward movement of the actuator end 58 to its lowermost position. If desired, the actuator 54 may have an intermediate or off position. In this position, the handle 56 is horizontally positioned and locked by suitable spring action, now well known, which holds the handle 56 and end 58 in horizontal position. The blade construction 24, 25 and 26 are also horizontal, in the off position, with the blades 24 and 26 separated from the blades 23 and 27. At this time, all of the blades are electrically separated from each other.

If desired, the blades 23-27 may have their terminal connector ends 34 pointed sidewise, as illustrated in FIG- URE 12. In FIGURE 12, a stack of blades is illustrated, before they are assembled with the remaining portions of the switch construction. The blade 23 is at the top, and the other blades underneath in the same order as in FIGURES 1 and 2. The blade 23 may have a sidewise formed connector tip 61A, to which an electrical conductor or wire, not shown, may be secured by soldering or the like. The blade 24, which is underneath the blade 23, may have an oppositely directed sidewise connector tip 62A to which a wire may also be secured. If desired, the blade 25 may have a straight tip 63A. However, this end 63 may be shorter than the others, if no wire is to be connected to it. The blade 26 is below blade 25 but is not visible in FIGURE 12. Blade 26 may have a sidewise directed tip directly under the tip 61A of FIGURE 12, and the blade 27, which also is not visible in FIGURE 12, may have an oppositely sidewise directed tip under the tip 62A of FIGURE 12.

These tips 61A-63A, and the invisible tips of blades 26 and 27 may be sidewise directed, as described in connection with FIGURE 12, or they may be straight, without any sidewise formation, as illustrated at 61-65 in FIGURES 1, 3 and 5. The sidewise formations of FIG- URE 12 provide a wider spacing between the tips 61A and 62A to permit easier soldering of conductor wires. The same is true of the sidewise tips, not shown, for the blades 26 and 27.

The blocks or holding members and 22 may be provided with integral plastic studs 66 and 68, which are molded during the original molding of the members 20 and 22.

The frame rails 46 and 48 may be provided with openings 70, 72 which may be assembled over the studs 66 and 68, as shown in FIGURE 5.

In assembling the switch, a plurality of switch blades 23-27, of the desired configuration are placed in the slots 42 of one of the blocks, such as in blocks 22, in FIGURES 3 and 4. The other block 20, is placed over the blades, as shown in FIGURES 3 and 4 and is brought downwardly, substantially to the dotted line position shown in FIGURES 3 and 4.

The rails 46 and 48 are placed against the outer sides of the blocks or holding members 20 and 22, as shown 4 in FIGURE 5, with the studs 66 and 68 in the openings 70 and 72. This switch assembly, as shown in FIGURE 5, is placed and pressed between the ultrasonic couplers 74 and 76 of an ultrasonic vibrating system or apparatus 78, now well known, which produces high frequency relative vibrations between the couplers 74 and 76.

These couplers 74 and 76 may each be provided with a surface 80 which ultimately will engage the outer surfaces of the rails 46 and 48. These surfaces 80 may also have indentations 82 which will engage the studs 66 and 68 to form the rail holding heads 84 by upsetting the studs 66 and 68 by the local heat produced by the vibrations. Also, if desired, the surfaces 80 may have flanges to straddle the rails 46 and 48.

Thereafter, the coupler surfaces 80 engage the rails 46 and 48, and produce the vibrations and local heat in the blocks 20 and 22, through the rails 46 and 48, to weld the blocks 20 and 22 together at their meeting surfaces 86.

The couplers 74 and 76 may be readily relatively movable toward and away from each other to insert and remove the switch assembly 18 into and from such couplers.

These couplers 74 and 76 may be connected respectively to the masses 75 and 77 which produce relative movement between the couplers 74 and 76 which produce local frictional heating action at the places to be described. The masses 75 and 77 are pressed toward each other, as indicated by the arrows.

The electrical terminals 79 may be connected to a DC polarization power supply and the terminals 79 may be connected to a high frequency AC power system to produce the desired vibrations in the transducer 81 and its connecting arm 81 which is connected to the coupler 74. The apparatus 78 is now available on the market. In general, it has the system herein disclosed, but may have equivalent variations therefrom. It may be adjusted to produce the desired frequencies and amplitudes of vibrations.

This welding operation firmly secures the switch parts together.

The grooves 42, if desired, may be made with converging walls 88, FIGURE 9, which are capable of receiving blades of varying thickness and width.

FIGURE 9A shows the walls 88 receiving blades of dilfer-ent thickness and width from that shown in FIG- URE 9. In FIGURES 9 and 9A the vibrations cause the blades to become embedded in the slanting walls 88, as indicated at 88' in dotted lines. The slant shown in FIG- URES 9 and 9A is greatly exaggerated, merely to illustrate the principle involved. In actual use, the slant is much less perceptible, since the blade structures in actual use do not have the large variation in size which is provided in FIGURES 9 and 9A.

If blades of relatively great difference in thickness and/ or width are to be used in the same stack, the groove 42 which are to receive them may be molded with suitable width and/ or depth to accommodate such diiferent blades.

FIGURE 11 shows another embodiment in which a spacer block 90 may be placed between the blocks 20 and 22 or between other blocks. The spacer block 90 may have grooves 92 which may be opposed or aligned with the grooves 42 of the blocks 20 and 22, so that a double row of blades may be assembled, as is shown in FIG- URE 11. If desired, more than one spacer block 90 may be used, so that more rows of blades may be provided. For example, if two spacer blocks 90 are used, side by side, then three rows of blades may be provided, and so on, depending on the number of spacer blocks that are used.

The words ultrasonic, ultrasonically, etc., as applied to the bonding or welding actions herein disclosed, are intended to indicate the use of ultrasonic, near ultrasonic and lower-frequency vibrations capable of upsetting, bonding or welding certain plastic parts herein disclosed. These vibrations are intended to produce local heat by the local friction of the parts to be upset or joined while they are being vibrated. This local heating action does not unduly heat the main bodies connected to the parts so upset, bonded or welded.

By way of example, the vibrations may be within the frequency range of 4000 to 20,000 cycles per second, more or less.

Any thermoplastic material may be used that is electrically insulative, is sufficiently rigid at temperatures normally encountered by such switch constructions, and can be locally bonded, welded or upset, as herein disclosed.

For example, high fusion temperature, thermoplastic materials such as polycarbonate, nylon, polysulfone, or any other similar thermoplastic, self-extinguishing material may be used. Lexon, manufactured by the General Electric Company, is a satisfactory thermoplastic material of this character.

Apparatus for practicing the method of this invention is on sale by Branson Instruments, Inc, of Danbury, Connecticut, and Cavitron Ultrasonics, Inc., of Long Island City, New York.

Thus it is to be seen that this invention provides a new, useful and unobvious switch construction and method of making the same.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims subject matter which follows:

What is claimed is:

1. In combination: a plurality of plastic switch blade holding members locally ultrasonically welded together; a plurality of switch blades having held portions held by ultrasonically welded portions of said holding members and having freely movable contact end portions extending outwardly from said holding members, an actuator carrying frame having frame portions engaging some of said holding members and being held by ultrasonically formed plastic attaching means on said last-named attaching means, and blade actuator means on said frame engaging an end portion of one of said blades.

2. In combination:

a plurality of plastic switch blade holding members locally ultrasonically welded together;

'and a plurality of switch blades having held portions held by ultrasonically welded portions of said holding members and having freely movable contact end portions extending outwardly from said holding members in which said blades are relatively wide and relatively thin compared to their 'width and said holding members each has parallel opposite sides with one of said opposite sides of each of said holding members having opposed relatively deep and relatively narrow grooves compared to their depth, said opposed grooves holding opposite edges of said blades.

3. A combination according to claim 2 in which there are two parallel holding members with a plurality of inwardly directed grooves on the inner sides of said holding members and said blades have notches which engage the ends of said holding members to prevent longitudinal displacement of said blades.

4. A combination according to claim 3 in which an actuator carrying frame has rail portions secured to the outer sides of said holding members by ultrasonically formed thermoplastic heads.

5. A combination according to claim 4 in which said frame member is a U-shaped frame member with said rail portions forming the legs of said U-shaped frame member.

6. A combination according to claim 5 in which blade actuator means is carried by the base of said U-shaped frame member, said actuator means actuating one of said blades.

7. A method comprising: forming a plurality of plastic switch blade holding members; placing a plurality of switch blades with held portions between said holding members and with movable end portions extending from said holding members; and ultrasonically welding said holding members together to lock in place said held portions of said blades, said holding members being formed with opposed sets of grooves to hold opposite edges of said blades and said blades being first placed downwardly in one of said sets of grooves, then the other of said sets of grooves being placed over opposite edges of said blades, and then said holding members being ultrasonically welded together to hold said blades in said grooves.

8. A method comprising: forming a plurality of plastic switch blade holding members; placing a plurality of switch blades with held portions between said holding members and with movable end portions extending from said holding members; ultrasonically welding said holding members together to lock in place said held portions of said blades, securing frame portions of an actuator holding frame to some of said holding members, and providing blade actuator means on said frame to engage an end portion of one of said blades.

9. A method according to claim 8 in which some of said blades are insulatedly fastened together adjacent said end portions to be moved in unison by said actuator means.

10. A method comprising: forming a plurality of plastic switch blade holding members; placing a plurality of switch blades with held portions between said holding members and with movable end portions extending from said holding members; and ultrasonically welding said holding members together to lock in place said held portions of said blades, said holding members being formed with opposed grooves to hold opposite edges of said blades.

11. A method according to claim 10 in which two parallel holding members are provided with a plurality of inwardly directed grooves on the inner sides of said members.

12. A method according to claim 11 in which an actuator holding frame is provided with rail portions which are secured to the outer sides of said holding members.

13. A method according to claim 12 in which said frame member is a U-shaped frame member with said rail portions forming the legs of said U-shaped frame member.

14. A method according to claim 13 in which blade actuator means is provided and is carried by the base of said U-shaped frame member, said actuator means actuating one of such blades.

15. In combination:

a plurality of electrically insulating, ultrasonically weldable blocks having switch blade holding notch means;

a plurality of electrically conducting switch blades having blade held portions held by said notch means all of said blades having opposite sets of blade ends extending out of said blocks with one set of ends being contact ends and with the other set of ends being electrical conductor attachment ends;

said blocks being ultrasonically welded together to hold said blade held portions by said notch means,

said one set of blade ends having movable blade portions which are movable to electrically closed and open positions in which switch frame members are placed against outer surfaces of said blocks and are ultrasonically welded to said blocks,

and in which said blades and blocks have interengaging holding means which are ultrasonically secured together,

and in which switch blade actuating means are carried by said frame members and actuate said movable blade portions,

and in which said notch means on one block are aligned 'with notch means on another block and said blade 7 held portions are blade edges which are held in said 3,254,188 notch means, 2,348,088 and in which said blade edges have offset portions to 3,022,814 hold said blades against longitudinal movement. 3,242,029 3,300,851

References Cited UNITED STATES PATENTS 2,727,103 12/1955 Barber 200-166 3,002,270 10/1961 DePrisco 219-78 Lohs 200-166 Nichlos et a1 200166 Bodine 15673 Deans 156380 Lodder 29-155.5

HERMAN o. JONES, Primary Examiner us. 01. X.R. 

